Fine-porosity ceramic coating via spps

Abstract

A process is provided for producing a fine-pored ceramic layer composed of zirconium oxide or gadolinium zirconate or ytterbium zirconate or europium zirconate or lanthanum zirconate on a substrate and/or on a metallic layer. The process includes spraying at least one water-soluble and dissolved salt. In the process, water soluble salts of zirconium and gadolinium or ytterbium or europium or lanthanum are added for the zirconates.

1 - 9 . (canceled) 
     
     
         10 . A process for producing a fine-pored ceramic layer composed of zirconium oxide or gadolinium zirconate or ytterbium zirconate or europium zirconate or lanthanum zirconate on a substrate and/or on a metallic layer, the process comprising:
 spraying at least one water-soluble and dissolved salt,   wherein water soluble salts of zirconium and gadolinium or ytterbium or europium or lanthanum are added for the zirconates.   
     
     
         11 . The process as claimed in  claim 10 , wherein the spraying is carried out by means of a plasma. 
     
     
         12 . The process as claimed in  claim 10 , wherein the salts of zirconium are selected from the group consisting of:
 zirconium tetrachloride: ZrCl 4 ,   zirconium tetraiodide: ZrI 4 ,   zirconium nitrate pentahydrate: Zr(NO 3 ) 4  5H 2 O,   zirconium sulfate: Zr(SO 4 ) 2 , and   zirconium sulfate tetrahydrate: Zr(SO 4 ) 2  4H 2 O.   
     
     
         13 . The process as claimed in  claim 10 , wherein the salts of gadolinium are selected from the group consisting of:
 gadolinium chloride: GdCl 3 ,   gadolinium chloride hexahydrate: GdCl 3  6H 2 O,   gadolinium bromide hexahydrate: GdBr 3  6H 2 O,   gadolinium iodide: GdI 3 , and   gadolinium nitrate hexahydrate: Gd(NO 3 ) 3 .   
     
     
         14 . The process as claimed in  claim 10 , wherein the salts of ytterbium are selected from the group consisting of:
 ytterbium(II) chloride: YbCl 2 ,   ytterbium(III) chloride hexahydrate: YbCl 3  6H 2 O,   ytterbium(II) bromide: YbBr 2 ,   ytterbium(III) bromide: YbBr 3 ,   ytterbium(II) iodide: YbI 2 , and   ytterbium(III) iodide: YbI 3 .   
     
     
         15 . The process as claimed in  claim 10 , wherein the salts of europium are selected from the group consisting of:
 europium(II) chloride: EuCl 2 ,   europium(II) bromide: EuBr 2 ,   europium(III) bromide: EuBr 3 ,   europium(II) iodide: EuI 2 ,   europium(III) iodide: EuI 3 , and   europium(III) nitrate: Eu(NO 3 ) 3 .   
     
     
         16 . The process as claimed in  claim 10 , wherein the salts of lanthanum are selected from the group consisting of:
 lanthanum chloride heptahydrate: LaCl 3  7H 2 O,   lanthanum chloride: LaCl 3 ,   lanthanum bromide heptahydrate: LaBr 3  7H 2 O, and   lanthanum iodide: LaI 3 .   
     
     
         17 . The process as claimed in  claim 10 , wherein a porosity in the range from 8% by volume to 25% by volume is set by use of salt solutions added in different amounts. 
     
     
         18 . The process as claimed in  claim 10 , further comprising setting materials gradients in the layer by mixing of salts. 
     
     
         19 . The process as claimed in  claim 10 , further comprising spraying nanoparticles concomitantly. 
     
     
         20 . The process as claimed in  claim 10 , wherein (Gd, Yb, La, Eu) salts of hafnium are used for hafnium oxide and/or hafnates. 
     
     
         21 . The process as claimed in  claim 10 , wherein a metallic substrate composed of a nickel- or cobalt-based superalloy is coated. 
     
     
         22 . The process as claimed in  claim 10 , wherein the metallic layer is a diffusion layer and/or overlay layer, in particular an MCrAl(Y) layer. 
     
     
         23 . The process as claimed in  claim 10 , wherein the salts oxidize and/or react with one another so as to form an oxide ceramic as coating. 
     
     
         24 . The process as claimed in  claim 10 , comprising producing a two-layer ceramic layer using the salts. 
     
     
         25 . The process as claimed in  claim 24 , wherein the two-layer ceramic layer comprises a lower zirconium oxide layer and an upper zirconate layer or hafnate layer, 
     
     
         26 . The process as claimed in  claim 25 , wherein the hafnate layer is gadolinium-based.